In a 40 ha section of Meijendel, a coastal dune area near The Hague in The Netherlands, no stabilization measures have been carried out since 1978. Colour-infrared airphotos at scale 1:2500 were used to follow blowout development through the years 1980, 1985, and 1990. Quantitative comparison of the images of the successive years needed careful matching with a photo-grammetrical approach for data acquisition, and data analysis with a GIS. Due to the locational precision afforded by the computational procedures, the analysis provided the following information: 1. total numbers of blowouts and their total area per year of survey, 2. geo-referenced position, form and area of each blowout, and the total surface of deflation per year of survey, and 3. changes between years of survey per blowout and per total area. Aerial photographs are particularly useful for monitoring landscape changes because the choice of the variables to be measured remains open during the course of the programme. Moreover the period of measurement can be extended towards the past. However the necessary photogrammetric procedures involved are relatively inaccessible to non-professional mappers.